The recent boom in fracking has turned America into the Saudi Arabia of natural gas, almost overnight.

Proponents say that this burgeoning industry has ensured U.S. energy independence for years to come, and created a more climate-friendly alternative to dirtier-burning fuels like coal and gas. It has arguably also hastened the demise of the coal industry, as power plants switch in large numbers to the cheaper gas, resulting in U.S. CO2 emissions sinking to their lowest levels in nearly two decades. And with less smog-producing particulates and deadly mercury in the air, we can hope that respiratory illnesses like asthma may begin to decline.

But fracking poses its own risks. While our air has been getting cleaner, opponents argue that America’s water has been getting dirtier as the result of the hydraulic fracturing of shale. Fracking uses lots of water—up to seven million gallons for every well drilled—which is mixed together with sand and a witch’s brew of industrial chemicals, then blasted a mile into the earth to the shale formations where the natural gas is located. This high pressure stream shatters the rock and releases the gas, which geysers up to the surface to be recovered.

But what exactly happens to the water which is shot into the earth? A study published today in the journal Science says that we don’t entirely know the answer to this yet—and what we don’t know may harm us.

The missing half

What we do know is that about half of the fracking fluid gushes back up to the surface. “People focus on what exactly are the chemicals that we are putting into frack fluid,” said Radisav Vidic, the lead author of the study and a professor at the University of Pittsburg, in a Science podcast. “But a more significant problem is what comes out—because the quality of what comes out is many, many times worse than the quality of the water that was injected into the well.”

That’s because the frack water picks up contaminants underground—a variety of salts, benzene, heavy metals, organic compounds and radioactive substances such as radium-226, which is found in high levels in the Marcellus Shale formation that is being fracked from West Virginia to Pennsylvania.

The hydraulic fracturing water cycle. Courtesy EPA

Vidic says that disposing of this briny and highly contaminated water can be a problem. Either it is re-injected deep into wells in the earth where, theoretically, it remains for perpetuity; or it is purified in a waste treatment facility and then either recycled or discharged into a river.

If all of this goes smoothly, our water supply remains pristine. But the study warns that accidents can, and do, happen. In one well-publicized incident, improperly treated fracking fluids were discharged into the Monongahela River, which provides drinking water for most of Pittsburgh, forcing 325,000 residents of the region to switch to bottled water for several weeks.

Another potential problem area is the roughly half of the water used in fracking which does not migrate back to the surface through the drilling shaft, but remains interred underground. Ideally, Vidic says, this contaminated water will never come in contact with the groundwater, which sits in the aquifer thousands of feet above it. But he adds that there is a lot that we still don’t know about how water moves underground.

A leaky system

Gas companies argue that the frack fluid is prevented from fouling the groundwater by the thick cap of bedrock which sits between it and the aquifer. However, the Pennsylvania researchers point out that geological formations are not watertight. There can be networks of fractures in the rock which permit toxic fracking fluids to flow back up towards the surface under certain circumstances.

Marcellus Shale underlies a U.S. East Coast region from New York to Virginia. Courtesy USGS

This flow underground might account for some of the reports of tainted water in wells near gas drilling sites. But there are also other ways that fracking fluids can get into our water; for example, through cracks in well casings, well blowouts, and surface spills from trucks or containment ponds. Anthony Ingraffea at Cornell University found that there was an 8.9 percent failure rate among wells in the Pennsylvania Marcellus region in 2012, and he predicts that leaks and other problems will become increasingly common as the wells age.

What kind of impacts might these leaks have? There have been numerous anecdotal reports of illnesses in people living near fracking wells, but not yet any long-term epidemiological studies. One stumbling block is that the chemical mix added to the fracking fluid is a mystery. Many of the scores of industrial chemicals being used are not currently regulated by the U.S. Safe Drinking Water Act, says the Science study, due to a loophole introduced by former Vice President Dick Cheney which exempts natural gas drilling from certain provisions of the environmental law. Drillers have so far refused to reveal their formulas, claiming this is proprietary information.

But Vidic and his colleagues say that companies need to disclose the exact composition of the injection fluid—information which is critical for scientists and regulators in their efforts to ensure water quality. The researchers also point out that states including Pennsylvania are not yet consistently collecting the kinds of hard data about surface water and well water quality which would allow us to assess the impact that fracking is having.

Until this monitoring takes place, they argue, fracking’s effect on our water supply is anybody’s guess.

Richard Schiffman is an environmental journalist, poet and author of two books based in New York City. You can read more of his work here.

Fracking is the best of the even worse alternatives when it comes to carbon fuels. The greens will not permit the construction of dams and hinder the nuclear industry as best they can. Wind and solar are a joke, let’s face it. Without exorbitant government (meaning, taxpayer) subsidies they are not viable. Spain and Germany learned that lesson; China has a $3 trillion surplus to fertilize their alternative industry with. Compared to carbon, alternatives are inconvenient and energy-poor. We’re not going to run the U.S. economy on Bald Eagle killing wind mills, ever. Which leaves fracking, the GMO food version of the energy sector. That’s the bridge to the next chapter in energy, be it fusion or some other tech as yet unimagined.

http://twitter.com/deweytheswede Kristin Dewey

You should watch “Frack Nation” because it will open your eyes. And yes, I’m for fracking if done responsibly. I live close to several oil/gas wells (don’t see money from it either), and our groundwater has been fine for the last 30 years (from when the first well was fracked/drilled).

http://www.chlorinesupplier.com/ Chlorine Supplier

Nice post! It will surely help a lot of people.

Geoffrey Mbaku

Hydraulic fracturing does not present any risk to our water supply. The technique uses lots of water, harmless additives, chemicals, and sand. The sand is the proppant which keeps the fractured rocks open thereby creating a channel for the natural gas to flow from the formation to the surface.

Now lets talk about the safety of our water supply. To do that we have to examine how the hole is drilled from the surface to the pay zone some 8500 ft down and then about 1500 ft horizontally. Typically our water supply is found around 200 to 300 ft below the surface. In some formations it can be as deep as 800 ft. From the surface down to about 100 ft when the well is being drilled, the inside hole is supported by a conductor casing. From that point down past the water supply zone, a surface casing is placed in the hole and cemented between the outside diameter of the casing and the ground formation. This isolates the water supply zone from the drilled hole and prevents any contamination of the water aquifer. After this point more casings are placed and cemented in the hole as it is being drilled to prevent any cross contamination either from the produced oil/gas to reservoir formation or vice versa.

What happens to all the water that was pumped into the ground during the hydraulic fracturing process? Well, that water plus the salt water that is found deep in the drilled hole flows back to the surface through the production tubing, inside all the cemented casings and recovered in a controlled manner.

The recovered water is sent to water treatment facilities where it is purified and sold back to oil & gas operations such cementing and hydraulic fracturing.

The safety of our water supply has always been and will always be number one ever since Halliburton performed the first commercial hydraulic fracturing treatment in 1949. Since then over 1 million oil/gas wells have been safely fractured in the United States and that will continue to be the case.